To evaluate the influence of immunosuppression and therapy with whole body irradiation and chemotherapy on the risk of new malignancies following bone marrow transplantation. The association between development of a new cancer, in particular, new solid tumors, and prolonged immune suppression from chronic GVHD and/or high dose radiation will be estimated. Cancer risk among the cohort of patients not exposed to immune suppression (autologous transplants) will be evaluated. Variation in risk by age at transplantation and time after transplantation will be quantified.